A composition for impregnating materials to shield against the effects of alternating electromagnetic fields, its application in coating/impregnating fibrous and/or porous matrices and materials containing the same

ABSTRACT

The object of the invention is a composition for impregnating other materials, rendering them able to shield alternating electromagnetic fields in the range from low frequencies up to radio frequencies, containing an aqueous solution of salt that may form hydrates or a combination of salts, of which at least one forms a hydrate, characterised in that it contains an acrylic and/or styrene-acrylic dispersion and/or silicone emulsion and/or enhancing additives selected from a group containing surfactants and/or aluminosilicates and silicates and/or soluble and insoluble calcium compounds, metal and metalloid oxides, while an alternating field is shielded at least in range from 10−2 Hz to 106 Hz and its application for coating/impregnating fibrous and/or porous matrix and materials containing the thereof.

The present invention relates to a composition for impregnating othermaterials, thus making them capable of shielding against the effects ofalternating electromagnetic fields, including its use in coating andmodifying construction materials, furniture, textiles, clothing andother materials. The invention can be applied in the constructionindustry, for household goods, for coating the structural elements ofbuildings and for shielding electrical and electronic devices.

The technological development of electromechanical, electronic,teletechnical and IT devices, as well as their rapidly increasingapplication, requires us to analyse the impact of electric (EF),magnetic (MF) and electromagnetic fields (EMF) on human health. Thefollowing organisations are involved in work on the problem: WHO (WorldHealth Organization), European Commission: HEALTH & CONSUMER PROTECTION,International Commission on Non-Ionizing Radiation Protection and IEEE(Institute of Electrical and Electronics Engineers). The analysis of thehealth condition in the USA during the rapid electrification process inthe 1940s indicates that electromagnetic radiation contributes more tocivilization diseases than the actual change of lifestyle [MedicalHypotheses 74(2010)337]. As we cannot give up using electrical devices,the only solution is to shield them. Classical materials for EFshielding are single-phase materials of high electric conductivity(metals, carbon, conductive polymers and their combinations) based onthe Faraday cage effect. Metal foils and grids placed, inside a polymeror glass, conductive polymers and materials made of cotton and polyesterwith woven-in micron diameter silver or stainless steel wires areapplied as EF shields [IEEE Trans. Electromagnetic Compatibility30(1988)187; ibid 30(1988)282].

These types of solutions are disclosed in U.S. Pat. No. 6,028,266—Lowfrequency MF shield and U.S. Pat. No. 6,320,123—EMF shielding, as wellas for electric cable shielding. A novel solution is the application ofmulti-phase materials to form composites for EMF shielding, because whentailoring the properties of the component phases, their weight/volumeratio and connectivity, one can obtain materials with properties suitedto the requirements of the intended application [J. Mater. Sci.44(2009)3917; Progress Mater. Sci. 59(2013)183].

Many patented solutions are related to EMF shielding composites in theGHz frequency range. This solution is disclosed, among others, in thefollowing patents: U.S. Pat. No. 3,599,210, EP 0312333B1, FR 2695760A1,EP0420513B1, U.S. Pat. No. 5,661,484, and JP10013081. There are otherinventions for EMF shielding composites having a wide range from Hz toGHz, such as in international patent application WO2002/40799A1, U.S.Pat. No. 6,337,125B1, international patent application WO2003031722A1and polish patent PL203956. A wide EMF shielding range (from Hz to GHz)was given in international patent application WO 2002/40799A1, where theshielding material used a composite based on a matrix filed withcements, plaster or gypsum combined with various ashes, slag,micro-silica and limestone (CaCO₃ with admixtures) and componentsreflecting/absorbing electromagnetic radiation, such as exfoliatedgraphite, electrode graphite, graphite flakes, carbon fibres, soot,ferrites and carborundum (SiC). The shielding material contains 1-6layers of metal grid and 0.5-60% w/w of iron filings. U.S. Pat. No.6,337,125B1 presents devices and methods for the production ofcomposites absorbing electromagnetic radiation that allows for increasedabsorption rate and are thinner and/or lighter than those previouslyused. These are a combination of synthetic dielectric materials eitherwith a synthetic magnetic material or another material with a highmagnetic losses such that the dielectric permittivity and magneticsusceptibility are matched in the desired frequency range. The frequencyabsorption band is from 10 MHz to 10 GHz.

International patent application WO2003/031722A1 shows a compositecomposed of a suitably selected layer to reflect electromagnetic wavesand an absorbing layer containing conductive fibres, e.g. carbon fibresof lengths chosen to suit the band of absorbed electromagnetic waves.

Polish patent PL203956B1 shows a material absorbing electromagneticwaves in a frequency band from a few kHz to ˜2 GHz as a nanocompositecomposed of kaolinite stripes of relatively low permittivity and layersof organic polar molecules of high permittivity. The kaolinite packagesare <1 nm thick, while a 0.2-2 nm layer of polar organic molecules is ofimidazole. This is polar organic molecules intercalated with kaolinite.

Chinese patent application CN103755333 presents a composite composed ofa matrix in the form of a silicone rubber foam filled withmagnesium-barium-aluminium nanoferrite. In this case the radiationabsorbent is nanoferrite; however the shielding frequency of thepatented composite is not specified.

Polish patent application PL387274 presents an aqueous solution forimpregnating materials to shield against alternating electric fieldswith low-frequency characteristics. This involves a liquid containing ahydratable salt or salt mixture from the set MgCl₂, Na₃PO₄, CuSO₄ andother hydratable salts, while the weight ratio of salt or salt mixturewith water is in the range 1:1 to 1:100, and with the optional additionof a polymer from a group used for applying finishes to textiles,especially poly(vinyl acetate). The Prior Art figure shown before thepresented invention demonstrates the absorption of an electric fieldusing a polyester material impregnated with an aqueous solution ofMgCl₂:H₂O in the ratio 1:20 with the addition of a poly(vinyl acetate)dispersion.

Generally applied EMF shields in the low-frequency range usingsingle-phase materials of high electric conductivity that are heavy,expensive and usually require grounding. Moreover, the majority ofshields use multi-phase systems: composites to shield EMF in themicrowave band or from few kHz to few GHz along with composites with aspecific shielding properties in the Hz-GHz range that also containmetal meshes and iron filling (thus require grounding). The searchcontinues for a material able to shield EMF starting from lowfrequencies, i.e. from 10⁻² Hz, to radio frequencies, i.e. up to 10⁶ Hzand higher, in the order of several GHz, without the need for groundingwhile remaining light and useable in various forms: foil, nonwoven,plaster, wall or wood, and could even shield at low relative humidities.Unexpectedly, all the above problems were solved by the presentedinvention.

The presented invention is a composition designed to impregnate othermaterials, thus rendering them able to shield against the effects ofalternating electromagnetic field. It contains an aqueous solution ofsalt that may form hydrates or combinations of salts, of which at leastone forms a hydrate, characterised by its content of an acrylic and/orstyrene-acrylic dispersion and/or silicone emulsion and/or enhancingadditives selected from a group containing surfactants and/oraluminosilicates and silicates and/or soluble and insoluble calciumcompounds, metal and metalloid oxides, while the alternating field isshielded at least in range from 10⁻² Hz to 10⁶ Hz. The composition,according to the invention, is preferably characterized by havingsurface active agents that are compounds selected from a groupcontaining detergents, surfactants, emulsifiers, amphiphiles, preferabledefoamers, dispersants, and glycols. The composition according to theinvention is preferably characterized in that aluminosilicates andsilicates are compounds selected from the group containing bentonite,kaolin, and talc. The composition according to the invention ispreferably characterized in that insoluble calcium compounds arecompounds selected from the group containing powdered limestone anddolomite. The composition according to the invention is preferablycharacterized by containing compounds selected from the group containinggypsum, calcium hydroxide, and Portland cement. The compositionaccording to the invention is preferably characterized by containingresins, preferably alkyd resin in an organic solvent, and epoxide resinin a solid state or solution, phenol formaldehyde resin in ethanol, orsilicone resin in solution or suspension. The compounds used that mayform inorganic hydrates are: MgCl₂ (MgCl_(z).6H₂O), CaCl₂ [CaCl₂.H₂O,CaCl₂.2H₂O, CaCl₂.6H₂O], NaCO₃ [NaCO₃.H₂O, NaCO₃.7H₂O, NaCO₃.10H₂O],LiCl [LiCl.H₂O, LiCl.8H₂O] and others. As polymer dispersions, acrylicdispersion, styrene-acrylic dispersion and silicone emulsion can beused. The invention can use as modifiers, surface active agents, i.e.defoamers as a silicone oil emulsion, dispersants such as sodiumpolyacrylate, anionic active emulsifiers and viscosity enhancers such ascarboxymethylcellulose and poly(ethylene oxide). As modifiers also thefollowing compounds can be used: basic magnesium silicate[Mg₃Si₄O₁₀(OH)₂-talc], basic aluminium silicate[Al₂Si₂O₅(OH)₄-kaolinite, the main component of kaolin] andaluminosilicates in form of bentonite, as well as calcium compounds:lime powder [>90% CaCO₃], dolomite powder [(Ca, Mg)(CO₃)₂], gypsum[CaSO₄.2H₂O] and Portland cement [3CaO.SiO₂ (50-65%), 2CaO.SiO₂ (˜20%),4CaO.Al₂O₃.Fe₂O₃ (˜10%) and 3CaO.Al₂O₃ (˜10%)]. It is preferable whenthe hydratable salt:water weight ratio is in the range from saltconcentration in saturated solution to 1:1,000, polymer:water ratio isin the range from 1:1 to 1:2,000, weight ratio of surface activeagents:water is in the range from 1:20 up to 1:10,000, while inorganicmodifiers:water weight ratio is in the range 1:0.5 up to 1,000. Equallypreferable for airtight gel shields, shielding occurs up to 3 GHz.

Another object of the invention is the use of the composition defined inthe first object for coating/impregnating fibrous and/or porousmatrices, which after drying obtain EMF shielding properties, preferablefor coating or modifying constructional, furniture, textile and clothingmaterials. Preferable construction materials according to the inventionare primers, plaster/paint primers, paints, plastering mortars,laminates used in constructions including: roof membranes, vapourbarrier laminates with particular application for roofs and otherapplications, vapour-permeable laminates, foils coated with theshielding solution, and textiles with shielding properties. Theinvention used as fibrous materials cellulose, viscose, polyester andother polymer nonwoven, spun and knitted fabrics, while as porousmaterials the following are used: cement, different bricks, plaster,gypsum board, plasterboard, cement board, OSB and similar materials ofdifferent commercial names, wood, laminates and various andvapour-permeable and vapour barrier roof membranes. Materialsimpregnated with composition such as nonwovens, spun or knittedmaterials or construction material such as cement, plaster, gypsumboard/plasterboard/cement board, ceramic materials, bricks, silicateblocks or wood form composite matrix, whose EMF absorbing materialsafter drying are bound with water in form of micro- and nanodropletsentrapped on the surface of pores/nanopores and modifier grains in formof hydration water (connected with salts forming hydrates) and waterabsorbed in bulk (bentonite) as well as dispersed polymer particles andintroduced modifier particles.

The third object of the invention is electrical field shielding forconstruction, furniture, textile or clothing material characterised inthat it contains the component material defined in the first object ofthe invention.

An essential feature of the invention is the development of theshielding composition for impregnation of fibrous and/or porousmaterials intended for shielding electromagnetic fields in the lowfrequency band of 10⁻² Hz up to radio frequencies, i.e. 10⁶ Hz. Thecomposition is a mixture of: an aqueous solution of one or more saltsable to form hydrates, a polymer dispersion (acrylic or styrene-acrylicdispersion or silicone emulsion) and/or modifiers (surface active agentsand/or silicates and aluminosilicates and/or water soluble and insolublecalcium compounds). Materials containing the composition according tothe invention such as nonwoven, spun or knitted materials and/orconstruction materials such as cements, gypsum board/plasterboard/cementboard, ceramic materials/bricks, silicate blocks and/or wood arecomposite matrices of statistic topology, which, after drying, shieldselectromagnetic radiation. The shielding properties of this compositeare related to dielectric absorption arising from the dielectric lossesof all composite components and with the Maxwell-Wagner polarizationoccurring in this composite related to the difference between thepermittivity of the matrix and fillers as well as of the entrapped waterand modifiers. By changing the type and topology of the matrix as wellas the type and concentration of the hydratable salt, concentration ofpolymer dispersion, type and concentration of modifiers, it is possibleto adjust the shielding frequency band to suit the requirements of theapplication.

It is preferable for the matrix to have pores and/or slits and/orcapillaries. Preferably a composite matrix belonging to the groupcontaining textiles, knitted materials, nonwovens, ceramics, wood,plastics, construction materials and various systems thereof. EMFshielding composites were produced and electric field shielding testswere carried out for different porous matrices such as ceramics,nonwoven and similar materials impregnated with impregnating solutionsof various compositions. The effect of matrix structure and type (suchas porosity, weight, hydrophilic properties) was studied, as well as theeffect of temperature and humidity. Shields manufactured according tothe invention can be used for the production of different types ofscreens to be used in construction, such as nonwoven roofing, roofmembranes, bricks, ceramic tiles, cement, mortar and plaster, paint,primers, putty or can be applied directly to a building wall to protectliving organisms and electronic devices against the effect ofalternating EMF. Shielding materials can also be used directly e.g. forelectrical outlets and electric cables. Another application of theimpregnating solution is the production of whole-bed mats. Screens witha matrix made of nonwoven, spun or knitted materials can be used alsofor the production of clothing, bedsheets, quilts, tents, sleeping bagsand foam pads. Protection of human health and electronic devices doesnot exhaust the uses of the present invention. The invention can be usedfor protecting rooms and buildings against electronic informationleakage, etc.

The Examples of the invention are presented in the figures, where

FIG. 1 presents the dependence of the real and imaginary part ofpermittivity (∈′, ∈″) and dielectric losses (tan δ) on frequency for afoil-screen produced on a production line,

FIG. 2 presents the dependency of shielding efficiency on frequency forvarious screens,

FIG. 3 presents a comparison of shielding efficiency dependence onfrequency for a screen in the form of 12 μm thick aluminium foil and ascreen containing gel and an aqueous solution of NH₄Cl and MgCl₂ withthe addition of SiO₂,

FIG. 4 presents a comparison of dependence of shielding efficiency onthe electric and magnetic component for a gel screen at a frequency of27 MHz,

FIG. 5 presents a comparison of dependence of shielding efficiency onfrequency for a screen containing an aqueous solution of gel NH₄Cl andMgCl₂ with the addition of SiO₂ and a screen containing additionally gelgellan,

FIG. 6 presents a comparison of dependence of shielding efficiency SE ofelectric field determined as SE=(E₀−E_(e))/E₀ as a percentage (E₀ is theelectric field strength before the screen, E_(e) is the electric fieldstrength behind the screen) on frequency for screens with a matrix inthe form of a polyethylene (PE) foil with calcium carbonate (CaCO₃)impregnated with various aqueous solutions of hydratable salts with theaddition of bentonite (specified percentage concentration of additivesare in wt percentage), while

FIG. 7 presents a comparison of shielding of the invention shown inpatent application PL387274 and composition according to the presentedinvention with additions for low humidity environments.

EXAMPLE 1

In order to illustrate the advantages of the invention, its performancewas compared with a prior known solution. As a typical prior art for thepresented invention, the invention shown in patent application PL387274is shown below, where a hydrophilic textile made of polyester wasimpregnated with an MgCl₂ solution at a temperature not exceeding 117°C. in order to obtain an EF shield. The solution was prepared in theweight ratio MgCl₂.6H₂O:H₂O equal to 1:20 with the addition of apoly(vinyl acetate) dispersion belonging to the group of polymers usedfor applying finishes to textiles in order to maintain the bondedhydrate. Subsequently, after draining, the fabric was dried and left toachieve ambient humidity—in order for separation of free water from thematerial to occur. After drying, the fabric absorbed the electricalcomponent of electromagnetic waves in the low frequency band. Theelectric field shielding ability was determined using a Maschek ESM-100.C&C generator FG-220C was used as the source of the alternating electricfield. Measurement results from 10¹ to 5×10⁴ Hz are presented in theillustration labelled state-of-the-art illustrating the dependence onthe frequency of electric field strength measured with an electric fieldmeter for the modified fabric obtained according to the proceduredescribed in Example 1 placed between the field meter and the antennaconnected to the generator (see the curve with measurement points markedwith squares, and the control measurement without modified fabric withmeasurement points marked with triangles). FIG. 7 presents a comparisonof the shielding of the invention shown in patent application PL387274and the composition according to the presented invention containing 2.2%of MgCl₂ with the addition of a 20% acrylic dispersion and 5% silica ata relative humidity in the range 25% to 37%.

Examples of the invention are presented in the Tables and in theillustration with figures presenting the measurement results ofshielding efficiency. The Table and illustration present the measurementresults of shielding efficiency (SE) SE=(E₀−E_(e))/E₀ (E₀—electric fieldstrength in front of the screen, E_(e)—electric field strength behindthe screen) or shielding efficiency in dB. Different matrices wereimpregnated with 16 g/m² of various compositions and then after 24 h theshielding efficiency was measured. The drying time of the impregnatedmatrix was chosen to be excessive, since as early as 10 h no changes inSE were observed. The polymers used in these examples were dispersionswith a dispersed phase:water ratio of 1:1. Electric field strength wasmeasured at ambient temperature using an electromagnetic field meter byMaschek Elektronik, ESM-100 3D H/E in the frequency range from 5 Hz to400 kHz. A rod antenna connected to a C&C FG-220C generator was used asthe source of the alternating electric field. For a polypropylenenonwoven impregnated with a shielding component material, dielectricmeasurements were also carried out at ambient temperature using abroadband dielectric spectrometer by Novocontrol GmbH in the frequencyrange from 10⁻² to 10⁷ Hz. Table 1 presents the increase of shieldingefficiency of a model wall made of a matrix (PE+CaCO₃) afterimpregnation with various impregnating solutions: an aqueous solution ofMgCl₂, a mixture of an aqueous solution of MgCl₂ with PVA dispersion anda mixture of an aqueous solution MgCl₂ with PVA dispersion and variousmodifiers. The first four results with figure labelled prior artillustrate the invention shown in Polish patent application PL387274.Depending on the modifier used, there was an increase in the shieldingefficiency (SE) and significant broadening of the shielding frequencyrange towards the higher frequencies in comparison to the closest priorart (see results starting from No. 5 in Table 1), while the 20%concentration of added dispersion of PVA is close to optimumconcentration. The further positions of Table 1 show the effect ofmodifiers: bentonite, sodium aluminosilicate, kaolin, titanium white,silica, talc, lime powder, dolomite powder, defoamer (emulsion ofsilicone oil, dispersant (sodium polyacrylate), poly(vinyl alcohol),carboxymethylcellulose and biocide (Kathon 886). Table 1 presentsshielding efficiency SE of an electric field determined asSE=(E₀−E_(e))/E₀ as a percentage (E₀ is the electric field strength infront of the screen, E_(e) is the electric field strength behind thescreen) for a matrix in the form of a polyethylene (PE) foil withcalcium carbonate (CaCO₃) impregnated with a mixture of an aqueoussolution of MgCl₂ with PVA dispersion and various modifiers (specifiedpercentage concentrations of additives are in wt percentage).

TABLE 1 2 5 10 20 50 100 200 400 No. matrix (PE + CaCO₃) + fillers kHzkHz kHz kHz kHz kHz kHz kHz 1 2.2% of MgCl₂ aqueous 24.7 8.8 4.4 2.9 2.42.4 1.9 2.9 solution (aq. s.) 2 2.2% MgCl₂ aq. s. + 0.1% PVA 53.2 30.014.9 8.5 5.4 5.6 6.1 8.2 dis. 3 2.2% MgCl₂ aq. s. + 20% PVA 76.6 62.142.1 23.6 15.3 11.9 9.2 7.7 dis. 4 2.2% MgCl₂ aq. s. + 95.4% 62.8 42.127.1 19.5 15.6 12.5 9.0 7.4 PVA dis. 5 no. 3 + 0.3% bentonite 97.8 95.994.1 92.2 85.7 77.3 65.3 52.9 6 no. 3 + 5% bentonite 97.2 95.8 95.0 92.281.3 70.6 51.0 30.0 7 no. 3 + 40% bentonite 82.9 64.4 43.9 24.6 8.9 4.13.1 4.2 8 no. 3 + 0.3% sodium 96.9 96.3 95.4 93.7 89.0 82.2 72.7 61.9aluminosilicate 9 no. 3 + 5% sodium 95.2 93.0 91.1 85.3 72.0 59.9 36.619.5 aluminosilicate 10 no. 3 + 20% sodium 90.3 78.3 64.2 45.3 21.6 11.55.1 2.0 aluminosilicate 11 no. 3 + 0.3% kaolin 97.4 96.7 95.5 91.5 81.068.5 49.2 29.1 12 no. 3 + 5% kaolin 96.5 96.2 94.9 92.3 82.1 72.6 49.934.4 13 no. 3 + 20% kaolin 96.4 95.8 94.7 91.9 81.9 68.5 49.4 27.1 14no. 3 + 0.3% titanium white 96.6 96.1 94.7 92.2 83.1 69.6 55.0 37.3 15no. 3 + 20% titanium white 97.1 96.9 96.2 94.2 86.8 77.5 62.8 45.6 16no. 3 + 40% titanium white 96.6 95.6 93.4 89.4 77.2 60.5 39.2 20.0 17no. 3 + 0.1% silica 96.7 95.5 94.6 91.7 82.4 72.3 53.6 30.8 18 no. 3 +5% silica 95.4 92.1 86.7 76.3 51.5 29.9 12.3 6.5 19 no. 3 + 10% silica94.6 90.9 86.5 76.1 53.0 33.5 13.2 9.2 20 no. 3 + 0.3% synth. lime 96.795.8 94.2 90.9 80.2 66.4 48.9 35.1 powder 21 no. 3 + 5% synth. limepowder 96.8 96.2 95.4 93.0 85.9 76.6 61.7 46.5 22 no. 3 + 20% synth.lime 96.6 95.4 93.4 89.4 76.0 59.6 40.8 25.3 powder 23 no. 3 + 0.3% nat.lime powder 96.8 96.2 95.5 92.9 84.3 72.6 55.7 35.8 24 no. 3 + 5% nat.lime powder 96.5 95.8 94.9 93.1 87.1 76.6 65.9 53.5 25 no. 3 + 20% nat.lime powder 96.8 96.3 95.6 93.9 87.5 79.4 65.7 51.8 26 no. 3 + 0.3%dolomite powder 97.2 96.5 94.8 90.9 79.3 64.6 44.4 25.2 27 no. 3 + 5%dolomite powder 97.0 96.4 95.9 93.2 86.2 78.5 65.5 49.1 28 no. 3 + 20%dolomite powder 96.9 96.8 96.2 94.9 89.2 80.9 68.6 54.2 29 no. 3 + 0.3%talc 96.9 96.1 94.9 91.4 80.8 69.5 51.4 30.3 30 no. 3 + 5% talc 96.996.5 95.8 94.3 88.1 79.3 67.5 55.7 31 no. 3 + 20% talc 96.1 93.7 90.184.0 69.5 52.3 31.4 16.4 32 no. 3 + 0.01% defoamer 96.8 96.2 95.2 92.884.9 72.3 55.2 37.1 33 no. 3 + 0.6% defoamer 96.3 94.2 90.3 83.2 64.542.1 20.7 9.8 34 no. 3 + 5% defoamer 67.6 48.5 32.4 23.3 16.2 14.6 11.111.4 35 no. 3 + 0.01% dispersant 95.8 95.3 94.4 91.6 82.9 71.8 53.8 35.136 no. 3 + 0.6% dispersant 97.0 94.8 92.0 86.3 72.0 54.6 32.4 18.3 37no. 3 + 5% dispersant 87.7 75.0 57.6 40.6 13.6 4.7 2.7 4.7 38 no. 3 +0.1% poly(vinyl 95.6 92.1 86.5 75.2 52.7 32.7 16.2 8.4 alcohol) 39 no.3 + 0.3% poly(vinyl 96.0 95.0 93.0 88.1 76.7 60.1 38.5 18.9 alcohol) 40no. 3 + 5% poly(vinyl alcohol) 96.1 93.8 89.7 82.4 63.6 42.9 22.8 11.141 no. 3 + 0.1% 96.7 94.4 90.1 81.5 65.1 45.8 27.4 16.7carboxymethylcellulose 42 no. 3 + 0.3% 96.4 93.9 89.6 80.8 60.7 39.921.3 10.4 carboxymethylcellulose 43 no. 3 + 1% 91.3 81.7 66.9 46.9 25.714.0 10.9 8.1 carboxymethylcellulose 44 no. 3 + 0.01% BIOCIDE 95.7 92.688.3 79.7 61.5 42.2 22.3 11.3 45 no. 3 + 0.1% BIOCIDE 96.1 95.0 93.287.4 75.8 59.2 33.9 17.0 46 no. 3 + 0.6% BIOCIDE 95.2 94.1 91.8 85.870.8 52.2 27.9 14.4

EXAMPLE 2

The tests carried out were as for Example 1, and Example 2 illustratestests of EF shielding efficiency depending on frequency for a shield inform of a polyethylene foil matrix with calcium carbonate (CaCO₃)impregnated with a mixture of an aqueous solution of MgCl₂ with acrylicdispersion and various modifiers (Table 2—shielding efficiency SE ofelectric field determined as SE=(E₀−E_(e))/E₀ as a percentage (E₀ is theelectric field strength in front of the screen, E_(e) is the electricfield strength behind the screen) for a matrix in the form of apolyethylene (PE) foil with calcium carbonate (CaCO₃) impregnated with amixture of an aqueous solution of MgCl₂ with acrylic dispersion andvarious modifiers (specified percentage concentrations of additives arein wt percentage).

TABLE 2 2 5 10 20 50 100 200 400 No. matrix (PE + CaCO₃) kHz kHz kHz kHzkHz kHz kHz kHz 1 2.2% MgCl2 Aqueous 24.7 8.8 4.4 2.9 2.4 2.4 1.9 2.9solution (aq. s.) 2 2.2% MgCl₂ aq. s. + 0.1% 25.0 7.9 3.8 2.5 2.5 2.62.3 3.3 acryl. dis. 3 2.2% MgCl₂ aq. s. + 20% PVA 35.6 16.5 10.5 8.1 6.65.6 4.3 4.3 dis. 4 2.2% MgCl₂ aq. s. + 95.4% 31.2 9.4 3.8 2.1 2.4 2.52.3 3.2 acryl. dis. 5 no. 3 + 0.3% bentonite 47.7 34.7 23.2 11.7 6.7 5.74.4 3.1 6 no. 3 + 1% bentonite 73.0 49.0 30.6 13.1 6.0 2.9 2.7 3.6 7 no.3 + 2% bentonite 67.3 41.6 21.4 12.8 6.1 4.8 4.7 5.1 8 no. 3 + 5%bentonite 64.3 37.5 22.0 13.7 8.4 6.3 4.4 4.5 9 no. 3 + 40% bentonite81.7 62.6 43.7 26.4 12.9 6.9 4.3 4.7 10 no. 3 + 0.3% sodium 47.4 27.119.6 15.3 12.3 9.8 6.8 7.0 aluminosilicate 11 no. 3 + 5% sodium 63.437.3 23.7 15.4 9.8 7.3 5.4 5.1 aluminosilicate 12 no. 3 + 20% sodium88.0 72.6 55.1 32.5 11.1 5.0 2.4 3.1 aluminosilicate 13 no. 3 + 0.3%kaolin 57.5 38.1 26.5 16.9 9.1 6.1 2.8 3.3 14 no. 3 + 5% kaolin 88.675.8 58.0 35.7 13.0 5.3 2.1 3.0 15 no. 3 + 20% kaolin 97.6 96.6 94.289.3 75.2 56.9 33.6 14.8 16 no. 3 + 0.3% titanium white 63.5 41.0 28.620.6 13.5 8.8 4.9 3.3 17 no. 3 + 20% titanium white 79.1 55.3 34.0 16.35.9 3.1 2.0 3.7 18 no. 3 + 40% titanium white 97.6 95.5 92.0 84.7 64.943.3 20.2 7.4 19 no. 3 + 0.1% silica 39.9 17.8 9.6 5.3 3.5 3.0 2.0 4.120 no. 3 + 2% silica 70.6 46.3 27.4 12.8 7.8 5.6 4.5 7.1 21 no. 3 + 5%silica 96.6 94.7 91.0 83.3 63.8 41.1 18.4 6.7 22 no. 3 + 10% silica 96.396.0 95.1 93.0 86.3 76.0 59.7 42.5 23 no. 3 + 0.3% nat. lime powder 58.631.4 15.5 7.4 3.6 2.6 2.0 4.2 24 no. 3 + 5% nat. lime powder 91.6 82.468.4 48.7 25.5 14.1 6.5 5.3 25 no. 3 + 20% nat. lime powder 85.4 67.749.3 30.5 17.3 12.2 8.6 8.1

EXAMPLE 3

The tests carried out were as for Example 1, and Example 3 illustratestests of EF shielding efficiency depending on frequency for a shield inform of a polyethylene foil matrix with calcium carbonate (CaCO₃)impregnated with a mixture of an aqueous solution of MgCl₂ withstyrene-acrylic dispersion and various modifiers (Table 3—shieldingefficiency SE of electric field determined as SE=(E₀−E_(e))/E₀ as apercentage (E₀ is the electric field strength in front of the screen,E_(e) is the electric field strength behind the screen) for a matrix inthe form of a polyethylene (PE) foil with calcium carbonate (CaCO₃)impregnated with a mixture of an aqueous solution of MgCl₂ withstyrene-acrylic dispersion and various modifiers (specified percentageconcentrations of additives are in wt percentage).

TABLE 3 2 5 10 20 50 100 200 400 No. matrix (PE + CaCO₃) kHz kHz kHz kHzkHz kHz kHz kHz 1 2.2% MgCl2 Aqueous 24.7 8.8 4.4 2.9 2.4 2.4 1.9 2.9solution (aq. s.) 2 2.2% MgCl₂ + 0.1% styr.-acr. 25.0 10.9 8.2 5.8 5.55.6 5.0 6.1 disp. 3 2.2% MgCl₂ + 20% styr.-acr. 29.7 15.3 9.9 6.5 6.04.9 3.0 4.2 disp. 4 2.2% MgCl₂ + 95.4% styr.-acr. 91.3 80.6 65.4 44.020.5 10.8 5.8 5.0 disp. 5 no. 3 + 0.3% bentonite 37.2 15.3 8.3 6.3 6.05.5 4.8 6.0 6 no. 3 + 5% bentonite 93.9 88.7 79.6 63.6 36.8 19.7 10.57.7 7 no. 3 + 40% bentonite 93.9 87.1 77.2 61.1 33.8 17.3 6.3 7.5 8 no.3 + 0.3% sodium 59.4 35.1 20.1 12.8 8.9 7.1 5.8 6.4 aluminosilicate 9no. 3 + 5% sodium 64.6 37.8 22.0 13.0 7.7 5.8 4.5 5.3 aluminosilicate 10no. 3 + 20% sodium 83.5 62.5 41.6 20.2 7.2 4.9 4.0 4.9 aluminosilicate11 no. 3 + 0.3% kaolin 27.7 9.3 4.6 3.2 3.1 3.1 2.7 3.5 12 no. 3 + 5%kaolin 56.8 30.6 20.0 12.8 9.5 9.1 7.4 8.7 13 no. 3 + 20% kaolin 96.494.6 90.2 82.2 62.3 40.4 20.5 10.2 14 no. 3 + 0.3% titanium white 47.224.0 13.7 9.0 6.7 5.6 4.7 5.3 15 no. 3 + 20% titanium white 97.0 94.991.4 84.2 64.8 42.8 21.5 9.9 16 no. 3 + 40% titanium white 95.9 94.792.2 87.1 72.4 52.3 28.9 12.3 17 no. 3 + 0.1% silica 42.2 19.7 10.7 5.84.1 3.5 2.7 3.3 18 no. 3 + 5% silica 96.4 96.1 95.0 92.4 84.4 72.5 53.734.2 19 no. 3 + 10% silica 96.1 94.3 85.6 83.5 65.1 43.7 23.3 10.8 20no. 3 + 0.3% synth. lime powder 31.6 10.0 4.3 2.9 2.8 2.9 2.3 3.3 21 no.3 + 5% synth. lime powder 70.0 45.9 29.1 18.1 11.1 8.0 5.7 5.9 22 no.3 + 20% synth. lime powder 87.4 71.7 52.7 28.6 11.6 5.1 2.1 3.1 23 no.3 + 0.3% nat. lime powder 38.3 14.7 6.8 4.2 3.3 2.9 2.0 3.2 24 no. 3 +5% nat. lime powder 71.7 46.8 28.1 14.7 7.2 4.5 2.8 3.7 25 no. 3 + 20%nat. lime powder 84.0 67.6 50.0 32.0 15.1 7.3 4.1 4.2 26 no. 3 + 0.3%talc 36.3 15.9 9.1 5.8 4.7 4.1 3.4 4.7 27 no. 3 + 5% talc 70.1 46.9 29.816.0 6.3 2.7 1.1 1.5 28 no. 3 + 20% talc 74.0 55.6 42.7 32.9 23.8 16.910.4 6.6

EXAMPLE 4

The tests carried out were as for Example 1, and Example 4 illustratestests of EF shielding efficiency depending on frequency for a shield inform of a polyethylene foil matrix with calcium carbonate (CaCO₃)impregnated with a mixture of an aqueous solution of MgCl₂ with asilicone emulsion and various modifiers (Table 4—shielding efficiency SEof an electric field determined as SE=(E₀−E_(e))/E₀ as a percentage (E₀is the electric field strength in front of the screen, E_(e) is theelectric field strength behind the screen) for a matrix in the form of apolyethylene (PE) foil with calcium carbonate (CaCO₃) impregnated with amixture of an aqueous solution of MgCl₂ with silicone emulsion andvarious modifiers (specified percentage concentrations of additives arein wt percentage).

TABLE 4 2 5 10 20 50 100 200 400 No. matrix (PE + CaCO₃) kHz kHz kHz kHzkHz kHz kHz kHz 1 2.2% MgCl₂ Aqueous 24.7 8.8 4.4 2.9 2.4 2.4 1.9 2.9solution (aq. s.) 2 2.2% MgCl₂ aq. s. + 0.1% sil. 95.8 93.6 90.8 85.468.1 51.8 32.3 18.5 emulsion 3 2.2% MgCl₂ aq. s. + 20% sil. 94.2 92.388.4 81.3 65.3 49.2 26.9 14.4 emulsion 4 2.2% MgCl₂ aq. s. + 95.4% sil.62.7 37.8 20.4 13.9 10.5 8.0 5.5 6.4 emulsion 5 2.2% MgCl₂ aq. s. + 0.3%tit. 36.4 13.7 8.8 6.2 5.1 4.8 4.6 4.7 white 6 2.2% MgCl₂ aq. s. + 20%tit. 38.1 20.3 12.7 8.5 7.7 5.7 4.2 4.2 white 7 2.2% MgCl₂ aq. s. + 40%tit. 97.2 96.2 94.2 90.4 79.6 63.7 43.2 24.0 white

EXAMPLE 5

The tests carried out were as for Example 1, and Example 5 illustratestests of EF shielding efficiency depending on frequency for a shield inform of a polyethylene foil matrix with calcium carbonate (CaCO₃)impregnated with an aqueous solution of MgCl₂ and various modifiers(Table 5—shielding efficiency SE of an electric field determined asSE=(E₀−E_(e))/E₀ as % (E₀ is the electric field strength in front of thescreen, E_(e) is the electric field strength behind the screen) for amatrix in the form of a polyethylene (PE) foil with calcium carbonate(CaCO₃) impregnated with an aqueous solution of MgCl₂ and variousmodifiers (specified percentage concentrations of additives are in wtpercentage).

TABLE 5 2 5 10 20 50 100 200 400 No. matrix (PE + CaCO₃) kHz kHz kHz kHzkHz kHz kHz kHz 1 2.2% MgCl₂ Aqueous 24.7 8.8 4.4 2.9 2.4 2.4 1.9 2.9solution (aq. s.) 2 no. 1 + 0.3% bentonite 79.9 65.6 51.2 33.9 18.6 10.65.6 3.9 3 no. 1 + 5% bentonite 96.4 96.0 95.6 94.8 92.6 87.9 77.9 69.9 4no. 1 + 40% bentonite 95.9 92.9 88.4 77.3 61.0 40.9 20.9 11.1 5 no. 1 +0.3% sod.-alum. 53.2 28.6 12.8 3.4 3.1 2.4 1.4 2.0 silicate 6 no. 1 + 5%sod.-alum. silicate 21.1 8.3 3.0 0.3 1.9 1.1 0.9 0.9 7 no. 1 + 20%sod.-alum. silicate 18.3 4.1 0.4 0.2 0.2 0.2 0.1 0.2 8 no. 1 + kaolin0.3% 90.9 84.1 79.3 75.9 68.5 55.9 40.5 30.6 9 no. 1 + 5% kaolin 96.094.8 92.9 89.2 80.2 68.2 52.9 43.3 10 no. 1 + 20% kaolin 97.3 97.1 96.895.9 92.4 86.3 76.8 67.0 11 no. 1 + 0.3% titanium white 86.3 79.7 73.962.7 40.3 21.9 8.5 4.2 12 no. 1 + 20% titanium white 95.5 92.4 86.5 75.852.1 28.0 12.1 8.1 13 no. 1 + 40% titanium white 97.1 96.0 93.6 89.576.4 58.8 42.4 26.4 14 no. 1 + 0.1% silica 87.3 79.5 69.6 54.1 32.5 15.86.6 2.7 15 no. 1 + 5% silica 73.4 52.7 34.4 18.9 10.9 7.2 4.9 4.5 16 no.1 + 10% silica 72.6 51.1 33.4 16.7 9.2 5.2 2.8 2.0 17 no. 1 + 0.3%synth. lime 59.0 35.7 19.4 8.7 6.5 5.0 3.6 4.1 powder 18 no. 1 + 5%synth. lime powder 94.1 93.8 93.5 92.4 88.8 81.3 70.5 60.7 19 no. 1 +20% synth. lime 96.8 96.2 95.2 93.1 87.5 78.7 66.4 52.7 powder 20 no.1 + 0.3% nat. lime powder 61.7 45.0 26.9 13.7 8.5 6.0 4.2 4.7 21 no. 1 +5% nat. lime powder 88.5 78.5 66.4 49.6 29.2 17.2 10.1 6.6 22 no. 1 +20% nat. lime powder 96.8 96.4 95.8 94.2 90.8 85.2 77.1 65.1 23 no. 1 +5% dolomite powder 85.0 76.1 66.6 50.3 28.4 14.9 7.3 6.5 24 no. 1 + 0.3%dolomite powder 76.6 63.4 48.8 29.6 15.2 7.9 3.8 3.4 25 no. 1 + 20%dolomite powder 96.4 96.3 96.3 96.1 94.9 93.2 90.4 82.8 26 no. 1 + 0.3%talc 76.6 59.6 43.6 23.7 12.4 6.6 3.1 2.1 27 no. 1 + 5% talc 96.5 96.496.3 95.7 93.0 87.6 77.4 70.0 28 no. 1 + 20% talc 96.1 95.6 95.0 93.387.4 78.0 61.7 48.7 29 no. 1 + 0.01% defoamer 39.9 17.5 8.1 4.4 4.3 3.32.5 2.8 30 no. 1 + 0.6% defoamer 86.1 77.7 69.9 56.2 33.5 16.4 4.8 2.231 no. 1 + 5% defoamer 56.8 33.8 19.8 9.6 6.3 3.7 1.4 0.9 32 no. 1 +0.01% dispersant 48.0 20.9 8.2 2.1 3.1 2.6 2.2 2.2 33 no. 1 + 0.6%dispersant 78.0 65.4 50.5 31.6 17.8 9.5 4.5 2.8 34 no. 1 + 5% dispersant80.3 68.6 54.0 36.2 17.2 7.5 3.0 1.7

EXAMPLE 6

The tests were conducted as for Example 1, and Example 6 illustratedresults of EF shielding efficiency tests depending on the frequency fora shield with a matrix in the form of a polyethylene foil (PE) withcalcium carbonate (CaCO₃) impregnated with an aqueous solution of MgCl₂with various modifiers (Table 6). Shielding efficiency SE of an electricfield of various frequencies determined as SE=(E₀−E_(e))/E₀ as apercentage (E₀ is the electric field strength in front of the screen,E_(e) is the electric field strength behind the screen) for a matrix inthe form of a polyethylene (PE) foil with calcium carbonate (CaCO₃)impregnated with an aqueous solution of MgCl₂ with various modifiers(specified percentage concentrations of additives are in wt percentage).

TABLE 6 2 5 10 20 50 100 200 400 No. matrix (PE + CaCO₃) kHz kHz kHz kHzkHz kHz kHz kHz 1 2.2% MgCl₂ Aqueous 24.7 8.8 4.4 2.9 2.4 2.4 1.9 2.9solution (aq. s.) 2 2.2% MgCl₂ + 0.6% empilan 81.8 63.6 42.5 28.0 10.77.3 6.6 8.6 2502 detergent 3 2.2% MgCl₂ + 0.6% elfacoze 73.3 56.3 41.126.7 15.4 10.8 8.1 7.2 200 detergent 4 2.2% MgCl₂ + 0.6% emulgin 72.962.6 46.6 29.5 13.6 6.4 4.5 3.7 5 2.2% MgCl₂ + 0.6% PEG 22 74.3 58.443.7 29.3 16.8 11.9 9.3 8.0

In summary it can be stated that it is possible to obtain EF shields ofhigh efficiency in a broad range of field frequencies. It is veryeffective to use a mixture of an aqueous solution of MgCl₂ withstyrene-acrylic dispersion, which has to be added in amount of: ˜90%(Table 3) and a silicone emulsion, where even the addition of fractionof a percent is active (Table 4). Shielding efficiency and frequencyrange is increased by addition of: modifiers, e.g. a few to few dozenpercent of bentonite, sodium aluminium silicate, titanium white, limeand dolomite powder and talc.

Subsequently, as can be seen in Examples 1-7, the optimum concentrationsof these additives when an aqueous solution of MgCl₂ is used depend bothon the matrix type and the type of polymer dispersion.

EXAMPLE 7

Loose construction materials (increasing shielding range) were added topowdered hexahydrated magnesium chloride in the ratio given in Table 7.The following materials were used: synthetic gypsum, natural gypsum,cement, and slaked lime, and comminuted to obtain a homogenous powdermixture. Water was added to the mixture to obtain a suitable consistencyand the mixture was used to coat a nonwoven polypropylene matrix of 25g/m² basic weight. After drying, an EF shield was obtained and shieldingefficiency measurements were carried out in the frequency range of 2kHz-400 kHz with the results given in Table 7 illustrating the shieldingefficiency SE of an electric field of various frequencies determined asSE=(E₀−E_(e))/E₀ as % (E₀ is the electric field strength in front of thescreen, E_(e) is the electric field strength behind the screen) for ashield prepared according to the above description (specified percentageconcentrations of additives are in wt percentage).

TABLE 7 2 5 10 20 50 100 200 400 No. Matrix: nonwoven kHz kHz kHz kHzkHz kHz kHz kHz 1 2.2% MgCl₂ Aqueous 84.4 68.7 54.8 40.5 25.0 14.1 8.15.3 solution (aq. s.) 2 aq.s. 50% synth. gypsum - 42.0 28.4 18.0 9.0 6.23.8 1.6 1.5 control 3 2.2% MgCl₂ aq. s. + 0.1% 95.8 93.6 89.5 81.6 63.642.4 24.3 13.0 synth. gypsum 4 2.2% MgCl₂ aq. s. + 5% 97.2 96.2 94.589.2 78.5 62.9 40.1 24.8 synth. gypsum 5 2.2% MgCl₂ aq. s. + 50% 97.897.6 96.8 95.0 89.4 80.8 70.0 58.5 synth. gypsum 6 2.2%MgCl₂ aq. s. +70% 98.0 97.7 97.1 95.2 90.5 83.0 70.2 56.6 synth. gypsum 7 nat.gypsum - control 41.4 27.0 17.0 8.7 6.7 4.6 2.8 3.6 8 2.2% MgCl₂ aq.s. + 0.1% nat. 96.9 95.8 93.2 88.1 73.7 55.6 35.0 18.0 gypsum 9 2.2%MgCl₂ aq. s. + 5% nat. 97.1 96.4 94.9 90.4 80.5 65.4 44.7 27.8 gypsum 102.2% MgCl₂ aq. s. + 50% nat. 96.8 96.9 96.8 96.3 94.1 89.8 83.2 74.9gypsum 11 2.2% MgCl₂ aq. s. + 70% nat. 96.9 96.8 96.2 94.2 89.0 80.164.1 48.8 gypsum 12 50% cement - control 2.8 1.3 0.6 0.2 0.1 0.3 0.2 0.613 2.2% MgCl₂ aq. s. + 0.1% 96.8 95.6 93.1 88.4 75.6 58.9 38.8 23.6cement 14 2.2% MgCl₂ aq. s. + 5% 97.0 96.4 94.9 90.8 80.9 66.2 46.1 30.6cement 15 2.2% MgCl₂ aq. s. + 10% 97.0 96.8 96.1 94.0 87.6 77.0 62.248.9 cement 16 2.2% MgCl₂ aq. s. + 30% 96.4 94.4 90.8 82.2 65.5 46.224.1 11.6 cement 17 2.2% MgCl₂ aq. s. + 50% 82.1 63.1 47.4 32.3 16.5 7.21.3 0.2 cement 18 2.2% MgCl₂ aq. s. + 70% 55.0 37.5 26.3 11.7 4.6 1.20.9 0.1 cement 19 2.2% MgCl₂ aq. s. + 0.1% 83.5 71.0 58.4 41.9 25.3 15.89.2 6.6 Ca(OH)2 20 2.2% MgCl₂ aq. s. + 0.6% 93.8 86.8 77.1 60.9 38.924.1 13.9 9.9 Ca(OH)2 21 2.2% MgCl₂ aq. s. + 5% 95.9 95.5 94.8 92.5 84.972.4 54.2 42.1 Ca(OH)2

EXAMPLE 8

An impregnating solution of the following composition: mixture of anaqueous 2.2% MgCl₂ solution with 20% PVA dispersion and 0.3% addition ofbentonite was applied to commercially available construction materialsin the form of:

-   -   a) plasterboard,    -   b) gypsum plaster wall,    -   c) OSB board.        The measured shielding efficiency for impregnated and dried        boards is specified in Table 8, showing the decrease in electric        field strength at the 50 Hz frequency due to the commercially        available construction materials in the form of boards, before        and after impregnation with a 2.2% MgCl₂ mixture of an aqueous        solution with 20% PVA dispersion and the addition of 0.3%        bentonite.

TABLE 8 Gypsum Plasterboard plaster wall OSB board V/m V/m V/m Electricfield strength 150 150 150 (control) Electric field strength after 137139 145 shielding with board Electric field strength after 4 3 6shielding with board painted once with shielding liquid Electric fieldstrength after 1 2 3 shielding with board painted twice with shieldingliquid

EXAMPLE 9

A foil-shield developed for protecting large surfaces (large devices,places of sleep) against low-frequency EF (up to approx. 20 kHz),produced on a production line. A polypropylene nonwoven of 25 g/m² basicweight was unwound continuously from a horizontally placed bale, draggedthrough a bath containing the impregnating solution at room temperature,than pressed using a mangle and dried at 95° C. (for 0.5 min at adistance of 5 m) and wound on a roll. The bath contained a mixture of a2.2% aqueous MgCl₂ solution with a 20% PVA dispersion with the additionof 0.5% of bentonite and 0.1% of silica. The basic weight of themodified nonwoven increased by 30% in comparison with the basic weightof the non-modified nonwoven. Subsequently, the nonwoven was subject toanother treatment involving hot drenching on both sides with apolyethylene film. Such a screen-foil is impermeable to water and can beused as roof insulation, under floors and in walls. Dielectricmeasurements (FIG. 1) show that the obtained screen-foil exhibitsdielectric losses (tan δ>1) in the low frequency range from 10⁻² Hz to10⁷ Hz. Dependence of shielding efficiency on frequency for this screenis presented by the curve with data points in FIG. 2.

EXAMPLE 10

A shielding laminate was developed for protecting large surfaces againstlow-frequency EF (up to approx. 20 kHz). Using the following substances:a mixture of 2.2% aqueous MgCl₂ solution, 20% PVA dispersion and 30%acrylic glue with the addition of 0.5% of bentonite and 0.1% of silica.The glue was used to join two layers of foil and, after drying atambient temperature for approx. one week, an EF shielding laminate wasobtained. The foils were made of vapour-permeable polyethylene foilswith calcium carbonate inclusions. The amount of glue used was 16 g per1 m² of the foil. Dependence of EF shielding efficiency for such alaminate on frequency is presented by the curve in FIG. 2, with datapoints.

EXAMPLE 11

Shielding floor underlay was developed to protect large surfaces againstlow-frequency EF (up to approx. 20 kHz), using the following substances:a mixture of a 2.2% aqueous MgCl₂ solution, 20% PVA dispersion and 3% ofacrylic glue with the addition of 0.5% of bentonite, 0.1% of silica, and0.3% of kaolin. The glue was sprayed on XPS floor underlays and dried at60° C. with ventilation. The amount of glue used was 5 g per 1 m² of theunderlay. The obtained material absorbs the electrical component of EMF,which is shown by the curve with data points in FIG. 2.

EXAMPLE 12

Shielding paint was produced using the following substances: a mixtureof a 2.2% aqueous MgCl₂ solution, 20% PVA dispersion and 0.4% bentonite,2% kaolin, 0.1% of silica, and 0.5% of surface active agents. Primerpaint (16 g/m²) intended for painting walls was applied with a paintingroll on porous foil made of polyethylene with calcium carbonateinclusions that simulated a wall. After drying the foil painted with theprimer shields low-frequency EF, as shown in Table 9 presenting theshielding efficiency SE of an electric field of various frequenciesdetermined as SE=(E₀−E_(e))/E₀ as a percentage (E₀ is the electric fieldstrength in front of the screen, E_(e) is the electric field strengthbehind the screen) for a matrix in the form of a polyethylene (PE) foilwith calcium carbonate (CaCO₃) painted with shielding primer.

TABLE 9 50 2 5 10 20 50 100 200 400 No. matrix (PE + CaCO₃) Hz kHz kHzkHz kHz kHz kHz kHz kHz 1 Shielding primer 98.9 97.1 95.3 92.2 85.8 67.249.1 27.7 12.0

EXAMPLE 13

A gel high-frequency EMF screen was developed in order to shieldequipment for nuclear magnetic resonance (NMR) and electron paramagneticresonance (EPR). The screen uses an encapsulated airtight gel producedon an aqueous base using 7% silica, 5% NH₄Cl, 5% MgCl₂ and 1% ofaluminium-sodium silicate. FIG. 3 presents the frequency characteristicsof the attenuation efficiency of the gel placed between two poly(vinylchloride) (PCV) foils, between which a nonwoven was placed to maintainthe fixed screen thickness. The thickness of the gel layer was 1 mm FIG.3 presents the shielding efficiency at a frequency of 27 MHz for thesame gel shield.

EXAMPLE 14

A gel high-frequency EMF screen was developed in order to shieldequipment for nuclear magnetic resonance (NMR) and electron paramagneticresonance (EPR). The screen uses an encapsulated airtight gel producedon an aqueous base using gellan, silica, ammonium chloride, andmagnesium chloride. FIG. 5 presents the frequency characteristics of SEof the gel with additives placed between the poly(vinyl chloride) foil,between which a nonwoven was placed to maintain a fixed screenthickness. The thickness of the gel layer was 1 mm.

Table 10 and 11 present a comparison of the EF shielding efficiency by ascreen using the same matrix with different fillers. Table 10 comparesthe 50 Hz EF shielding efficiency of the screen using a matrix in theform of a polyethylene (PE) foil with calcium carbonate (CaCO₃)impregnated with various impregnating solutions, while Table 11 presentsthe shielding efficiency of a polypropylene nonwoven impregnated with anaqueous MgCl₂ solution with various modifiers in percentage.

TABLE 10 styr.- acrylic silicone acryl PVA without dispersion dispersiondispersion dispersion polymer no. Matrix (PE + CaCO₃) [dB] [dB] [dB][dB] [dB] 1 2.2% MgCl₂ Aqueous x x x x 10.4 solution (aq. s.) 2 2.2%MgCl₂ aq. s. + 0.1% 4.4 53.7 5.3 14.7 x polym. disp. 3 2.2% MgCl₂ aq.s. + 20% polym. 6.0 46.3 5.5 42.4 x disp. 4 2.2% MgCl₂ aq. s. + 95.4%4.5 6.7 19.6 16.5 x polym. disp. 5 no. 3 + 0.3% bentonite 9.0 9.6 10.749.2 24.0 6 no. 3 + 5% bentonite 11.0 9.2 39.7 49.2 44.1 7 no. 3 + 40%bentonite 14.1 17.0 33.1 25.3 47.7 8 no. 3 + 0.3% sod.-alum. silicate9.0 9.8 11.7 51.2 16.0 9 no. 3 + 5% sod.-alum. silicate 8.2 24.2 15.759.7 20.1 10 no. 3 + 20% sod.-alum. silicate 24.3 15.6 17.3 34.3 20.5 11no. 3 + 0.3% kaolin 7.4 8.8 12.0 49.2 21.7 12 no. 3 + 5% kaolin 26.7 4.910.7 49.2 45.2 13 no. 3 + 20% kaolin 57.2 53.7 42.4 47.7 46.3 14 no. 3 +0.3% titanium white 6.5 9.2 8.4 49.2 17.8 15 no. 3 + 20% titanium white18.9 6.8 53.7 51.2 45.2 16 no. 3 + 40% titanium white 47.7 53.7 53.753.7 42.4 17 no. 3 + 0.1% silica 7.6 5.3 12.2 53.7 21.7 18 no. 3 + 5%silica 49.2 9.3 59.7 57.2 31.2 19 no. 3 + 10% silica 59.7 35.3 47.7 44.132.9 20 no. 3 + 0.3% synth. lime powder 8.9 7.9 10.8 57.2 19.3 21 no.3 + 5% synth. lime powder 12.1 8.6 7.3 51.2 42.4 22 no. 3 + 20% synth.lime powder 25.7 38.1 29.2 53.7 44.1 23 no. 3 + 0.3% nat. lime powder9.1 10.0 14.8 49.2 21.1 24 no. 3 + 5% nat. lime powder 10.8 14.8 11.249.2 35.3 25 no. 3 + 20% nat. lime powder 16.9 27.4 15.9 47.7 46.3 26no. 3 + 0.3% dolomite powder 8.6 8.5 11.9 63.2 17.8 27 no. 3 + 5%dolomite powder 8.6 10.6 11.8 49.2 16.4 28 no. 3 + 20% dolomite powder39.1 28.4 34.3 49.2 40.3 29 no. 3 + 0.3% talc 8.0 8.0 9.9 51.2 16.9 30no. 3 + 5% talc 8.5 7.9 11.5 51.2 42.4 31 no. 3 + 20% talc 17.7 29.625.4 57.2 44.1 32 no. 3 + 0.01% defoamer 7.6 8.2 11.8 48.4 19.7 33 no.3 + 0.6% defoamer 7.8 9.5 14.5 46.3 18.6 34 no. 3 + 5% defoamer 7.0 7.010.6 41.6 17.7 35 no. 3 + 0.01% dispersant 5.6 7.8 11.3 49.2 21.2 36 no.3 + 0.6% dispersant 7.9 7.1 9.1 53.7 16.2 37 no. 3 + 5% dispersant 6.06.1 11.2 43.2 16.5 38 no. 3 + 0.1% poly(vinyl alcohol) x x x 53.7 x 39no. 3 + 0.3% poly(vinyl alcohol) x x x 46.3 x 40 no. 3 + 5% poly (vinylalcohol) x x x 47.7 x 41 no. 3 + 0.1% x x x 46.3 xcarboxymethylcellulose 42 no. 3 + 0.3% x x x 53.7 xcarboxymethylcellulose 43 no. 3 + 1% x x x 47.7 x carboxymethylcellulose44 no. 3 + 0.01% BIOCIDE x x x 51.2 x 45 no. 3 + 0.1% BIOCIDE x x x 53.7x 46 no. 3 + 0.6% BIOCIDE x x x 45.2 x 47 0.1% MgCl₂ aqueous solution xx x x  0.6 48 MgCl₂ saturated aqueous x x x x  8.3 solution

TABLE 11 2 5 10 20 50 100 200 400 No. PP nonwoven matrix kHz kHz kHz kHzkHz kHz kHz kHz 1 2.2% MgCl₂ aqueous 84.4 68.7 54.8 40.5 25.0 14.1 8.15.3 solution (aq. s.) 2 2.2% MgCl₂ aq. s. + 0.6% 93.9 87.0 77.2 61.842.2 26.7 14.8 9.3 propylene glycol 3 2.2% MgCl₂ + 0.6% Euxyl 96.5 93.688.5 77.9 58.1 39.1 20.3 9.3 K120 preservative 4 2.2% MgCl₂ + 0.6% Euxyl95.4 92.1 86.4 77.1 57.4 38.5 23.9 14.0 K702 preservative 5 2.2% MgCl₂ +0.6% Euxyl 96.5 93.4 93.5 78.9 59.0 41.9 26.4 15.0 9010 preservative 62.2% MgCl₂ + 0.6% 94.5 87.6 77.2 62.5 40.9 23.2 9.9 3.4 Mystic Zenfragrance composition

1. A composition or impregnating materials, rendering them able toshield alternating electromagnetic fields and containing an aqueoussolution of salt that may form hydrates or a combination of salts, ofwhich at least one forms a hydrate characterised in that it containsacrylic and/or styrene-acrylic dispersion and/or silicone emulsionand/or enhancing additives selected from a group containing surfactantsand/or aluminosilicates and silicates and/or soluble and insolublecalcium compounds, metal and metalloid oxides, while the alternatingfield is shielded at least in the range 10⁻² Hz to 10⁶ Hz.
 2. Thecomposition of claim 1, characterised in that surface active agents arecompounds selected from a group containing detergents, surfactants,emulsifiers, amphiphiles, preferably defoamers, dispersants, andglycols.
 3. The composition of claim 1, characterised in thataluminosilicate and silicates are selected compounds from a groupcontaining bentonite, kaolin, and talc.
 4. The composition of claim 1,characterised in that insoluble calcium compounds are selected compoundsfrom a group containing powdered limestone and dolomite.
 5. Thecomposition of claim 1, characterised in that it contains compoundsselected from a group containing gypsum, calcium hydroxide, and Portlandcement.
 6. The composition of claim 1, characterised in that it containsresins, preferably alkyd resin in organic solvent, and epoxide resin ina solid state or solution, phenol formaldehyde resin in ethanol, orsilicone resin in solution or suspension.
 7. The composition of claim 1,characterised in that for airtight gel shields shielding occurs up to 3GHz.
 8. Use of the composition defined in claims 1 to 6 forcoating/impregnating fibrous and/or porous matrix, which after dryingobtain EMF shielding properties, preferable for coating or modifyingconstruction, furniture, textile and clothing materials.
 9. The use ofclaim 8, characterised in that construction materials are primers,plaster/paint primers, paints, plastering mortars, laminates used inconstructions including: roof membranes, vapour barrier laminates withparticular application for roofs and other applications,vapour-permeable laminates, foils coated with shielding solution, andtextiles with shielding properties.
 10. Electric field shieldingconstruction, furniture, and textile or clothing material characterisedin that it contains the composition defined in claim 1.